ClickHouse/src/Common/filesystemHelpers.cpp
2021-05-08 19:13:10 +03:00

112 lines
3.3 KiB
C++

#include "filesystemHelpers.h"
#include <sys/stat.h>
#if defined(__linux__)
# include <cstdio>
# include <mntent.h>
#endif
#include <cerrno>
#include <Poco/File.h>
#include <Poco/Path.h>
#include <Poco/Version.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
extern const int SYSTEM_ERROR;
extern const int NOT_IMPLEMENTED;
extern const int CANNOT_STATVFS;
}
struct statvfs getStatVFS(const String & path)
{
struct statvfs fs;
while (statvfs(path.c_str(), &fs) != 0)
{
if (errno == EINTR)
continue;
throwFromErrnoWithPath("Could not calculate available disk space (statvfs)", path, ErrorCodes::CANNOT_STATVFS);
}
return fs;
}
bool enoughSpaceInDirectory(const std::string & path [[maybe_unused]], size_t data_size [[maybe_unused]])
{
#if POCO_VERSION >= 0x01090000
auto free_space = Poco::File(path).freeSpace();
return data_size <= free_space;
#else
return true;
#endif
}
std::unique_ptr<TemporaryFile> createTemporaryFile(const std::string & path)
{
Poco::File(path).createDirectories();
/// NOTE: std::make_shared cannot use protected constructors
return std::make_unique<TemporaryFile>(path);
}
std::filesystem::path getMountPoint(std::filesystem::path absolute_path)
{
if (absolute_path.is_relative())
throw Exception("Path is relative. It's a bug.", ErrorCodes::LOGICAL_ERROR);
absolute_path = std::filesystem::canonical(absolute_path);
const auto get_device_id = [](const std::filesystem::path & p)
{
struct stat st;
if (stat(p.c_str(), &st)) /// NOTE: man stat does not list EINTR as possible error
throwFromErrnoWithPath("Cannot stat " + p.string(), p.string(), ErrorCodes::SYSTEM_ERROR);
return st.st_dev;
};
/// If /some/path/to/dir/ and /some/path/to/ have different device id,
/// then device which contains /some/path/to/dir/filename is mounted to /some/path/to/dir/
auto device_id = get_device_id(absolute_path);
while (absolute_path.has_relative_path())
{
auto parent = absolute_path.parent_path();
auto parent_device_id = get_device_id(parent);
if (device_id != parent_device_id)
return absolute_path;
absolute_path = parent;
}
return absolute_path;
}
/// Returns name of filesystem mounted to mount_point
#if !defined(__linux__)
[[noreturn]]
#endif
String getFilesystemName([[maybe_unused]] const String & mount_point)
{
#if defined(__linux__)
FILE * mounted_filesystems = setmntent("/etc/mtab", "r");
if (!mounted_filesystems)
throw DB::Exception("Cannot open /etc/mtab to get name of filesystem", ErrorCodes::SYSTEM_ERROR);
mntent fs_info;
constexpr size_t buf_size = 4096; /// The same as buffer used for getmntent in glibc. It can happen that it's not enough
std::vector<char> buf(buf_size);
while (getmntent_r(mounted_filesystems, &fs_info, buf.data(), buf_size) && fs_info.mnt_dir != mount_point)
;
endmntent(mounted_filesystems);
if (fs_info.mnt_dir != mount_point)
throw DB::Exception("Cannot find name of filesystem by mount point " + mount_point, ErrorCodes::SYSTEM_ERROR);
return fs_info.mnt_fsname;
#else
throw DB::Exception("The function getFilesystemName is supported on Linux only", ErrorCodes::NOT_IMPLEMENTED);
#endif
}
}